SB 11.17.45

sarvāḥ samuddhared rājā
 piteva vyasanāt prajāḥ
ātmānam ātmanā dhīro
 yathā gaja-patir gajān
Synonyms: 
sarvāḥ — all; samuddharet — must uplift; rājā — the king; pitā — a father; iva — like; vyasanāt — from difficulties; prajāḥ — the citizens; ātmānam — himself; ātmana — by himself; dhīraḥ — fearless; yathā — just as; gaja-patiḥ — a bull elephant; gajān — the other elephants.
Translation: 
Just as the chief bull elephant protects all other elephants in his herd and defends himself as well, similarly, a fearless king, just like a father, must save all of the citizens from difficulty and also protect himself.
Purport: 

Lord Kṛṣṇa, having concluded His discussion of brahminical duties, now describes the character and activities of a king. Protecting all of the citizens from difficulty is an essential duty for the king.